Four years driving a Z with a 355/144 blower has taught me this about temps. You can't compare any non-blown car's temp readings with yours, period. In around town driving 190* to 200* at a stoplight is normal. Highway drivng doesn't bring the temp down they go up. At 70-75 mph 210* is normal and may even creep a bit up depending on outside temps. This is not a concern. I have a 2-speed Ford Taurus set-up with the low speed coming on at 180* and the high speed at 210*. I have the alum. rad. and Edelbrock Victor hp water pump and it makes no diff. My fan is always runnig at low speed in town and will at some point switch to high on the freeway and runs at high till you get off the freeway. It's the nature off the beast of a blower motor. A lot of heat is always being generated. Get use to it or take the blower off.
When you say you are overheating do you mean your temp goes to 210*??? That's not overheating with a blower motor, that's normal.
If your boiling in the rad. or puking water than you have another problem that you better find.
LARRY